Respons Pertumbuhan Bibit Salak (Salacca edulis L.) terhadap Dosis Spora Endomikoriza pada Media Pembawa Pasir Vulkanik dan Pasir Laut

Response of Salak Seedling (Salacca edulis L.) Growth to Endomycorrhizal Spore Doses on Volcanic Sand and Sea Sand Carrier. Endomycorrhizae has several benefits, such as increase water absorption and nutrients of plant, protect plants from root pathogens and toxic substances, play a role in improving soil structure, and increase nutrient solubility. This study aimed to determine the growth response of salak seedlings to doses of endomycorrhizal spores in media carrying volcanic sand and sea sand. This study used a factorial randomized block design (RBD) with two treatments i.e. the number of spores and the type of carriers media. The results showed no significant interaction between the number of mycorrhizal spores doses with the carrier media on all observed variables. Spores doses significantly affected stem diameter and root mycorrhizal infection variables. The highest stem diameter was achieved at the dose of 75 spores that was 1.60 cm which was significantly different from control (1.28 cm), whereas the highest root infection was obtained at the dose of 225 spores (92.50%) which significantly higher than control (36.25%). At the observation of 4 MAP (month after planting) the highest root infection was obtained at the dose of 150 spores (82.50%) compared to control (10.00%). Volcanic sand carrier media produced the highest plant dry weight (3.59 g) which was significantly different to the sea sand (2.43 g).

Desain Kontrol Sistem Telemetri pH Larutan Nutrisi Hidroponik Berbasis Fuzzy Logic

The utilization of bare areas like narrow tract, building roof, or unused warehouse can be maximized as agricultural land using hydroponics system. Hydroponics is a cultivation technique by using nutrient solution. The plant nutrient is an alternative soil which relate with water acidity (pH), that has reaction with nutrient solubility to plant fertility. In fact, pH of the nutrients can change because of many factors like media of plant. The temperature of nutrient solution affect an ion nutrient absorption by plant root. The higher temperature reduces plant root ability to absorb water and ion nutrients. The more advanced technological developments, the agriculture can be controlled automatically and monitored remotely. The aim of this research is to make design control ph, volume and nutrients solution using fuzzy logic and zigbee pro communication for telematics control of plant hydroponics. The result of this experiment shown that fuzzy logic has effectiveness to control pH of hydroponics. It needs 429 seconds to setting point of range pH 5 ppm to 7 ppm and 459 seconds to setting point of range pH 9 ppm to 7 ppm.

Increasing intake of dietary soluble nutrients affects digesta passage rate in the stomach of growing pigs

The passage rate of solids and liquids through the gastrointestinal tract differs. Increased dietary nutrient solubility causes nutrients to shift from the solid to the liquid digesta fraction and potentially affect digesta passage kinetics. We quantified: (1) the effect of three levels of dietary nutrient solubility (8, 19 and 31 % of soluble protein and sucrose in the diet) at high feed intake level (S) and (2) the effect of lowv.high feed intake level (F), on digesta passage kinetics in forty male growing pigs. The mean retention time (MRT) of solids and liquids in the stomach and small intestine was assessed using TiO2and Cr-EDTA, respectively. In addition, physicochemical properties of digesta were evaluated. Overall, solids were retained longer than liquids in the stomach (2·0 h,P<0·0001) and stomach+small intestine (1·6 h,P<0·001). When S increased, MRT in stomach decreased by 1·3 h for solids (P=0·01) and 0·7 h for liquids (P=0·002) but only at the highest level of S. When F increased using low-soluble nutrients, MRT in stomach increased by 0·8 h for solids (P=0·041) and 0·7 h for liquids (P=0·0001). Dietary treatments did not affect water-binding capacity and viscosity of digesta. In the stomach of growing pigs, dietary nutrient solubility affects digesta MRT in a non-linear manner, while feed intake level increases digesta MRT depending on dietary nutrient solubility. Results can be used to improve predictions on the kinetics of nutrient passage and thereby of nutrient digestion and absorption in the gastrointestinal tract.

Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating

The low-efficiency problem in fertilizer application can be overcome by controlling fertilizer solubility, i.e. by rendering the fertilizer to be released gradually; such material is also known as slow-release fertilizer (SRF). This research was aimed to formulate SRF by coating technique using acrylic and chitosan as the coating material, and to evaluate fertilizer resistance to too fast disintegration, and rate of nutrient release method. The results demonstrated that fertilizer formulation containing N, P, K, Fe, Cu, and Zn with granulation technique yielded 74% of granules with 2-5 mm in diameter. The SRFs (formulated fertilizer with acrylic or chitosan coating) were more resistant to water pounding than non-SRF. Furthermore, shaking test with distilled water or 2% citric acid, or by percolation test with distilled water showed that the SRFs had lower nutrient solubility than the non-SRFs. The results of shaking test also specifically indicated that coating with acrylic made the fertilizer more resistant to the citric acid,suggesting that this coating material would be more suitable in acidic soils. The SRFs formulated with the addition of chitosan during blending of micronutrients prior to mixing with macronutrients, granulation, and final coating exhibited lower nutrient solubility than the SRFs without the pre-coating chitosan addition. [How to Cite: Lili H, G Djajakirana, Darmawan, and CP Munoz. 2015. Slow- Release Fertilizer Formulation Using Acrylic and Chitosan Coating. J Trop Soils 19: 37-45. Doi: 10.5400/jts.2015.20.1.37][Permalink/DOI: www.dx.doi.org/10.5400/jts.2015.20.1.37]

Solubility Characteristics and Slow-Release Mechanism of Nitrogen from Organic-Inorganic Compound Coated Urea

A soil incubation method was used to investigate the solubility characteristics and slow-release mechanism of organic-inorganic compound coated urea at temperature of 10, 20, and 30°C. The membrane microstructure with and without incubation was tested via scanning electron microscopy (SEM). Slow release of nitrogen (N) from different inorganic minerals was analysed by the activation energy from the nutrient solubility system. The rate of nitrogen solubility increased with temperature increasing. The first-order reaction kinetic equation described the solubility process of coated urea. The rate constantkalso increased with temperature increasing. Moreover, the SEM images showed that the microstructure of the coating layer changed into a flocculent structure and the number of tiny pores and holes on the membrane surface increased significantly with temperature increasing, which increased N solubility rate. The Arrhenius equation indicated that activation energy was closely related tokduring the solubility process; the activation energy was reduced withkrising, which resulted in N solubility rate increasing. Overall, the N solubility rate of coated urea was affected by temperature.

Nutrient Uptake in Container-grown Impatiens and Petunia in Response to Root Substrate pH and Applied Micronutrient Concentration

The objective was to quantify the effect of substrate pH and micronutrient concentration on tissue nutrient levels in Petunia ×hybrida Hort. Vilm.-Andr. and Impatiens wallerana Hook. F. Plants were grown in 10-cm-diameter pots for 4 weeks in a 70% peat: 30% perlite medium amended with five lime rates to achieve substrate pH values ranging from pH 4.4 to 7.0. Plants were irrigated with (in mg·L-1) 210N-31P-235K-200Ca-49Mg. Micronutrients were applied as an EDTA (ethylenedinitrilotetraacetic acid) chelated micronutrient blend (C111), at 1×, 2×, and 4× concentrations of 0.50Fe-0.25Mn-0.025Zn-0.04Cu-0.075B-0.01Mo. Patterns of tissue concentrations across substrate pH differed from nutrient solubility in the medium, particularly with regard to Mn. Foliar N content decreased slightly as substrate pH increased, whereas foliar Ca, Mg, and S increased. Although foliar P and K varied with pH, there was no consistent trend between species. Foliar total Fe, ferrous Fe, and Cu decreased as substrate pH increased, whereas foliar Zn increased. Foliar Mn content decreased for both species as pH rose to 6.0, and then increased from pH 6.0 to 7.0. In contrast, Mn level in the substrate, measured in a saturated medium extract using deionized water as the extractant, decreased as pH increased from pH 4.4 to 7.0. Chlorophyll content decreased when the ratio of tissue Fe to Mn was <0.57 (impatiens) or <0.71 (petunia), or Fe was <106 (impatiens) or 112 (petunia) μg·g-1. SPAD chlorophyll index also declined in petunia with foliar Mn >42 μg·g-1. Increasing C111 increased foliar Cu, total Fe and ferrous Fe in both species, and B for impatiens, and partly compensated for reduced nutrient solubility at high pH.